Automatic calendar



Jan. 7,193.6. A. K. H. GERMUNDssoN 2,026,882

' AUTOMATIC CALENDAR I Filed July 7, 1934 "12 Sheets-Sheet l A K. H.@CHW/msm /M/g/v 'n l Jan. '7, 1936. A, K, H. GERMUNDSSON 2,025,882

AUTOMATI C CALENDAR Filed July '7, 1934 12 Sheets-Sheet 2 A- 17u n wf.,2f ,20 lg. h ed 3 gi 'if Q27 W f 4/ 5 I 3g 15 M n 6 /qwwmssm //Y VEN770k Jan 7 1936- A. K. H. GERMUNDSSON 2,026,832

AUTOMATIC CALENDAR Fileduuly' 7,- 1954 12 sheets-sheet '5 jm 7, w36- A.K. H. GERMUNDSSON 2,@262

AUTOMATIC CALENDAR Filed July '7, 1934 12 sheets-sheet 4 H. K. H. Em/fzMassa/v /A/ :f5/V Wd@ A. K. H. GERMUNDSSON AUTOMATIC CALENDAR 12Sheets-Sheet 5 Filed July: '7, 19:54

Y )Vg W m ,N Wm Mw am nm Jan. 57, 936. A. K. H. GERMUNSSON 2,026,832

AUTOMATIC CALENDAR Filed July 7, 1934 l2 Sheets-Sheet 6 Hmm 7, w36., VA.K, H. GERMuNDssoN 2,026,8@2

AUTOMATIC CALENDAR Filed July 7, 1954 12 Sheets-Sheet '7 s HTW/Wray.

JM 7 w36 A. K. H. GERMUNDssoN 2,026,82

AUTOMAT I C CALENDAR Filed July 7, 1934 l2 Sheets-Sheet 8 Jam. 7, w3. A,K. H, GERMUNDSSON 2,026,8@2

AUTOMATIC CALENDAR Filed July 7, 1954 l2 Sheets-Sheet 9 im. "f7, 1936.`A. K. H. nG-ERMUNDssoN 2,@26832 AUTOMAT I C CALENDAR Filed July 7, 1,934l2 SheeLS-Sheet 10 A. K.v Hi GERMUNDSSON 2,026,8@2

AUTOMAT I C CALENDAR Jan. 7, 1936.

l2 Shee'cS-Sheet ll Filed July '7, 1934 Jan. 7, 1936. A. K. H.GERMUNDssoN 2,1026382 AUTOMATIC CALENDAR Filed July '7; 1954 12sheets-sheer 12 Patented Jan. 7, 1936 Z,

UNITED STATES PATENT OFFICE AJTOM'AT'IC oALENnARl Agne ns HerbertGermundsson, Stockholm,

.Sweden A'ppliw'tim'n:July v, 19s4,fsr'ia1"N0. 734,111 In Sweden July15, 1933 `7 claims. (o1. 1c-i12) ,lheV present invention relates toandautomatic catoridrum cylinder, Figures 12 and 14 showing., calendarin which indicators having .marked the. parts'looking from the right inFigurev 4, thereon ythe names of the days of` theweek, the Figure 16looking from the left in ligurefln@4 u date figure or figures, the monthnames, and` iig- Figures 13, 15 and 17 are horizontal sectional 5 ures`giving thenumber of the year are advanced views of the sameparts. 5byfaclockwork under the inuence of periodical .Figures 18 to 25 arediagrams of the mecha.v

external impulses, and has for its objectto pronism'for equalizing thedifferent lengths of the Vide an improved driving mechanism for suchmonths. Y .f .f n.

,t apparatus. f With thlsobject in` viewv there is The indicator drumsand the mechanism for 10 according to the invention included between theriving same are arranged within a casing (Fig. 10 driving mechanism forthe date figure indicators ure 1) provided with an aperture throughwhich and thedriving mechanism Yfor the monthname the-'positions of theindicator drums may be ob indicatorr an arrangement-adapting thecalendar served. In a frame l (Figures 3 to 6) is jour-.-

15 months, said arrangement consisting of a difdrums and ratchet Wheelsare in turn journalled., 15 ferentialmechanism which at the beginning ofOnto the left hand end of the spindle, as viewed. eachrmonthadjusts themechanism for shifting inFigure 4, is keyed the rotor 3 of a turning thename of themonth to operate as many days.` magnet which is adapted toreceive electrical im-1.

,earlieras the month has a number of daysless pulses from an externalcurrent source, in some month, on completion of the shifting operation,of calendars, and which is adapted for each suchl again adds as manydays so that the date indiimpulse to turn the shaft 2 one seventh o1' acomcators always pass-the position 31 before the date plete revolution(counter-clockwise according to` numeral 1 of the next month appears. i.v Figure-5,!clockwise according to Figure 6). Nearmentotthe inven'tion:f f eating kthe unit numbers oi the-date, viz.- the date Figure, 1 is afront view of the calendar. 1 I unit drum 4, the hub of which is shaped.to form .Figure is a side elevation thereof looking aL sleevesurrounding the spindle and. extending,- frorn ,the-left in Figure'l. lalong rthe whole indicator drum cylinder both to.-`

theoasing removed. v To the left of the indicator drum lcylinder. there4`Figure 5l is a horizontal sectional view of the is'keyed onto thissleeve a ratchet wheel 5 (Figa. calendar. o y n .i 1- ures 5, 7 and 8)and to the right of said cylinder. ,Figures 5 and 6 are crosssectionalfviews taken 1 there is keyed to the. same: sleeve thesun wheelshow the arrangement of the ratchet wheelsand On the sleeve of the drum4.;isjournalled asleeve theradial arms formi g parts of the calendarconnecting the drum indicating the tennumbers mechanism. f, l a v g ,Ygp of the date, viz. the date tens drumfl (Figures 4,;

Figures 7 and Sareian end View and a longi` 8 and -9), with the ratchetwheel- 8 positionedto.

thelefthand end of thecylinder of indicator 4, 7 and 8). On the sleeveof the drum lis.K

indicator drums with the appertaining -tens as viewed in Figure 4.- andjournalled on its sleeve. transfer'mechanism. Figure` 10 is a crosssec-y is the month name drum Il the hubof which isV tional view taken onthe line Illl0 in Figure 9. provided with a sleeve-like extension bymeans @Figure 11 shows the drum indicating the tens ofwhich the monthname drum isfrigidly con-1.-

wheel. In order to show more clearlyv the tens right of the series ofindicator drums. .To the transfer mechanismy the parts `in Figures `9 to11 right of the month name drum and journalled-on are-not set for thesame date as in Figuresfl to 6.rr its-sleeve-like extension are arrangedinthe ordern;` lguresl2,. l4, and 1.6 are end views ofl parts ofmentioned the hundreds, tens, and 4units `drumsthe mechan to-indcate`correctly the different lengths of the nailed a longitudinal spindle 2on which all s 20 than 3l and which at the end of each such short casesfrom a central source common to a plurality 20 Referring to the drawingsshowing an embodi"l est 'to`v the spindle is journalled the drumindi- 30Figure iS a front View of the calendar with the left and to the right asviewed in -Figure onthe lines 5*,5 and 6 6 in Figureflwhichgviews 6(Figures 12, 14 and l5) -of a .planetary gear. 35i

*0 tudinalcrOSs sectional View 0f the mechanism; at. the left of theindicator drum cylinder (Figures .40

drums .as viewed `in Figure 3. journalled the-day name drum 9 (Figures 4and'.

.Figures 7a, 7 Zi,l and 7c are diagrams showing 8) the left end surfaceof which is shaped to form @thesame mechanism in'dierentpositions.- aratchet `wheel Il) (Figures 4, 5, 7 and 8).. 45 Figure 9 is a verticalsectional view of the datev YPositioned to the right of the date units4drum 45 d0 digits of the `date Withvits appertaining ratchet nectedwith the ratchet Wheel I2positioned'to the-50 m at the right hand end ofthe indi- I3, lll and I5 which together indicate the number 55 I of theyear. The year units drum I5 is at its right hand end' face shaped toform a pinion I6 (Figures 4, 13, 15 and 1'1) 'Ihe pinion 6 meshes with aplanet wheel I1 (Figures 14 and 15) journalled on a ratchet sector I8(Figures 4, 6 and 12) which in turn is journalled on the spindle 2. Theplanet wheel I1 meshes on its outer side with gear teeth formed on theinside of the rim of a register wheel I9 (Figures 12 and 13) which isjournalled on the sleeve-like extension of the date units drum 4 betweenthe pinion 6 and the ratchet wheel I2.

Parallelly with the spindle 2 and above the series of drums there isfixedly arranged in the frame a spindle 20 on which is journalled asleeve 2l which at its right hand end, as viewed in Figure 4, carries acontrol pawl 22 (Figures 4, 6, 12, 13, 18 to 25) adapted to engage anotch 45 in the periphery of the register wheel I9. The control pawl 22receives its movement through the intermedium of the sleeve 2I from thelever 24 (Figure '1) which is adapted to be actuated by two pins 25, 26projecting from the ratchet wheel 8 connected to the date tens drum(Figures 'I and 8) v In addition to the control pawl 22, therecooperates with the ratchet sector I8 also a detent 21 (Figures 6, 12,13, 18 to 25) which is pivotally secured to the outer end of the radialarm 28 keyed to the spindle-2. The ratchet sector I8 is also adapted tobe actuated by a detent 29 pivoted in the frame and provided with an arm30 which can be actuated by the pin 3I on the month ratchet wheel I2.

To the left of the cylinder of drums as viewed lin Figure 4 there iskeyed to the spindle 2 a radial arm 33 (Figures 5 and '7) which at itsouter end is provided with two movable feed pawls 34, 35 of which theupper one 34 is adapted to engage the ratchet wheel I0 of the day namedrum and the lower one 35 the ratchet wheels 5 and 8 of the two dateindicating drums.

The date drums as well as the drums indicating the names of the weekdays, the names of the months, and the number of the year are providedwith snap springs 39 secured in the frame and adapted to retain thedrums in definite positions. In order to explain the manner of operationof the apparatus it will be assumed initially that the apparatus is seton one of the rst days in a month having 31 days, for instance the monthof January, and that the turning magnet 3 is connected to a centralclock or some corresponding arrangement which sends out one impulseevery 24 hours (at twelve oclock in the night).

On receiving such an impulse the driving magnet 3 turns the spindle 2one seventh of a revolution counter-clockwise, as viewed in Figures 5and '1, the arm 33 then turning through the same angle. The spindle 2together with the arm 33 is then turned back through the same angle by aspring (not shown on the drawings), the feed pawl 34 then advancing theratchet wheel I0 one seventh of a revolution the feed pawl 35 on theother hand advancing the ratchet wheel 5 only one tenth of a revolutionon account of the shape of its periphery. Through the movement of theratchet wheel I0, the day name drum 9 is turned so that a new day nameappears in the aperture of the casing. In turning the ratchet wheel 5 anew unit number of the date appears, and simultaneously the pinion 6(Figures 14 and 15) is turned one tenth of a revolution said movementbeing transferred by means of the planet wheel I1 to the register wheelI9.

When the next following impulses are received the movements describedare repeated until the unit number 8 of the date has appeared. Whenafter having been actuated by the next impulse the rocking arm 33 isturned back by its spring 5 the feed pawl 35 will advance the date unitsdrum 4 from position 9 to position 0. At the same time the tens drum 1and thus also the ratchet wheel 3 is turned from position 0 to position1 by means of the coupling mechanism shown in Fig- 10 ures 9 to 11. Inthe date units drum 4 is radially disposed a pin 36 which is adapted tobe pressed towards the centre against the action of a blade spring 31 adistance sufficient for the pin to engage a notch in the date tens drums'I (Figure 10). 15 This occurs when the outer end of the pin 36 passesthe snap spring 38 secured in the frame. The pin 36 will then take alongthe date tens drums 1 one tenth of a revolution. At the end of saidturning movement the drum 1 receives 20 a further impulse in the samedirection, because a snap spring 39 secured in the frame presses againstthe periphery of the drum which is shaped as a regular Octagon therebyforcing the drum 1 to perform one eighth instead of one25 tenth of arevolution. During the performance of said additional turning movementthe pin 36 releases the date tens drum 1 under the influence of thespring 31.

On receipt of the following impulses the' cal- S0 endar will show thedate numbers II to and inclusive 30 and the corresponding week daynames. When the date number 30 is indicated the ratchet wheels 5 and 8of the date units drum and date tens ydrum occupy the mutual positionsshown 35 in Figure '1a.

As above said and visible in Figure 10 the date tens drum is divided ineight parts. Its front faces (under the aperture) are marked with thefigures 1, 2, 3, (blank), 1, 2, 3, (blank) and the 40 drum makes onerevolution in two months, a blank face being shown for the dates 1 to 9,the figure 1 for the dates 10 to 19, the figure 2 for the dates 20 to29, and the figure 3 for the dates 30 and 31 only.

On receipt of the next impulse and the consequent turning of the spindle2 the shifting fro'm date numeral 30 to 31 (Figures '1 and 7a) iseffected in the following manner. On the clockwise restoring movement ofthe arm 33 the feed pawl 50 35 would advance the date tens wheel 8 aswell as the units wheel 5 if this were not prevented by a pin 40 securedto the side of the wheel 5 near its periphery and immediately adjacentthe notch 4I for the date numeral 1. This notch is deeper 55 than theothers in the same wheel and somewhat deeper than the two projections 43in the tens wheel 8, i. e. the points of the latter projections arepositioned at a shorter distance from the turning axis than the point ofthe notch 4I. 50 Through the action of the pin 40 the feed pawl 35 willduring its return movement be brought to such a position that itsextremity passes across the projection 43 of the tens wheel but engagesthe notch 4I of the units wheel 5, the wheel 5 65 being then steppedforward to the position shown in Figure '1. When sluiting from the date10 to the date 11, or from the date 20 to the date 21, the projections43 of the tens wheel have been turned away so that they are out of reachfor the feed pawl 35. The latter will then advance only theunits wheel.

Upon receipt of an impulse for shifting from the date numeral 31 to thedate numeral 1 of the next month (Figure 7b) the feed pawl 35 will luf;

engage durinjgtherreturnmveme'nt of' the Sbdle'?? i lar-'raffina'I'l'iearnr 42L 1s now'positioned under the pin 4D.' The Vdrivingarrangement for the month drum I'I andf'itsra'tchetwheel I2 is shown inFigures and`13 and in thediagrams of Figuresv 18 to will then advancethe ratchet Wheel I2 one step. The wheel I2 is provided with twelveperipheral notches and should thereforebe'turned only one twelfth ofa'revolul tion' at a'A time. The' diirerence is equalized by the 25K- i,Y

the notch only in case the control pawl 22 is en'- gagingVV the notch45' of the register' Wheel I 9. The notches in the'periphery of theWheel I2 are ofdiierentdepths depending upon Whether the corresponding'month has 28,V 30 o'r31 days, so that'ift'thedepthof thesoineivhatarther fromy the centre ythan the bottom o'ff'then'otch 48.The

notch' 50 corresponds to the intercalary day in" a'niannei" to be moreclosely describedloelovv'. The bottomof the notch 5IY `is` positioned atthesame distancefrom the N centre 'asthe bottom of the notch 48v(correspondigtoth nionth of February 'in an vordinary year,

i. el iri` a year that'is nota leap year)'. They nth'es 46 lie so farYfrom-the centrethatA theirV bottoms will extend outside'the'portion ofthe L, periphery of:v the" sector designated with the numeral 52.` l

Whenshifting from thevv position shown' in Figi ure'lZ 'f(31st4 Januaryin an'ordinary year) the controlpawlZZ is' in engagement with the notch45a`nd' the feed pawl 2I will the'zreforeV engage the notch 48 and'alsothe notch 5I. The wheel I2 isthe'rebyv steppedforward onetwelfth of arevolution. At the same time the ratchet sector I8f`is` stepped'iorwardthe same'ang'le and in additio'thefurthe l1/9() of a revolution, Whichisrequired 'in vorder that it shall be able to advance the register WheelI9 3/30 of a revolution. This 1's`V broight about by the planet Wheel I1rolling on "thesun-Whel 6'; which has thesam'e radius and the samenum'ber'of teeth as the wheel I`I,` the 'Wheel"|1 thereby driving' the'toothed rirnof theregister 'wheel vI9',"vvl'1`iclf1 has three times asgreat a radius and three times as lmany teeth as the Wheel HI'I- (Figure18).l 'I'herestoringof the )sector` I8't its initial positipnis"prevented 3,@ is weken-throughs@ serenita1 riiguem cooperates with theWheely 5` connectedv with the"A 1111551drum-r,` ,t `The month' name drumnow showsthe monthj and Ai'fljefeed pawl' ZTengage a notch on receiptvof the next impulse but for the control pawl bel' ing arrested by theperiphery of the register yWheel under the extremity of the Ycontrolpawl `22. The calendar then indicates the 28th of February (Figure'20).The control'pawl 22 now engagesu the notch 45 under the action 0f thespring sa' (Figl 4drure 12). v v

On receipt of the next impulse the feed pav'vly 21 will consequentlyengage the notch 46 representing the month of March and advance thevmonth drum one twelfth of a revolution so that 455:"

with the detent 29 so that the latter releases 'the`50'j sector I8. Thesector will then under the acf-` tion of the spring 455 (Figure 6)return to its initial position shownn in Figure 12. Since the" controlpawl 22'is still in engagement with the notch'VV the 'register Wheel I9is locked against 55%.

counter-'clockwise movement. For this reason the planet Wheel I'IUWillroll against the wheelv I9 and drive the wheel 6 3/10 of a lrevolution*counter-clockwise as. viewed in Figure 20. TheV units drum is herebyadvanced three days (from 60 the numeral 8 to the numeral l in theaperture). Simultaneously herewith the tens drum is also advancedthrough the intermedium of the coupling mechanism above described(Figures v9 to 65 11) from the position indicating the numeral2 to theposition indicating thev numeral 3. The calendar now indicates the date31, the indication March appears in the aperture, and the arm n 28 AisYin its advanced position (in its'right hand T7015 position accordingtoFigures 18 to V25). Onfthe'vv coihter-olockwise restoring movement lofthe arn` 28 upon the ceasing of the impulse the tens digit 3 disappearsand lthe control pawl 22 Vis lifted' in the'abovedescentesmanerfwherefrthe ,75

the feed pawl 21 out of reach from the notches of the month ratchetwheel I2 until the date 10 appears, the control pawl then slidingaccording to the above along the periphery of the register wheel I9.Since on the 1st of March the notch "45 was positioned under theextremity of the control pawl 22 and the wheel I9 is turned 1/30 of arevolution in every 24 hours the notch 45 will on the 31st of Marchagain be positioned directly Vunder the extremity of the control pawlwhich `then engages the notch 45 so that the month drum can be advancedto show a new month. The feed pawl 21 then engages the notch 41 in theratchet wheel I2 as well as the notch 49 in the sector I8, ,said twonotches having the same depth, and

'turns the wheel together with the sector clockwise. In this case thesector I8 is advanced only so far that the register wheel I9 is causedby means of the planetary gear to move 1/30 of va revolution. The sectoris locked in this position by means of the detent 29 the parts thenoccupying the position shown in Figure 22. The calendar now indicatesthe 1st of April.

During the month of April the week day drum and the date drums areadvanced as above de scribed. When the date numeral 30 has appeared inthe aperture the notch 45 is again positioned directly under theextremity of the control pawl 22, the extremity then engaging the notch.On receipt of the next impulse the feed pawl 21 'engages the notch 46and advances the month ratchet wheel I2 so that the month of May appearsin the aperture of the casing. The pin 54 on the wheel I2 lifts thedetent 29 out of engagement with the sector I8 by means of the arm 39.

'The sector I8 then returns to its initial position while turning, bymeans of the planetary gear, the pinion 8 together with the date drum 4one tenth of a revolution, so that the date 31 appears in thecomingaperture. In the return movement of the arm 28 the tens drum isadvanced from position 3 to a position showing a blank surface andsimultaneously herewith the control pawl 22 is lifted. The calendar nowindicates the 1st of May.

At the moment of shifting from the month of December to the month ofJanuary, i. e. to a new year, the month ratchet wheel I2 has turned sofar counter-clockwise according to Figure 16 that the toothed wheel 55'is engaged by the pin 56 secured in the frame and is thereby turnedclockwise one fourth of a revolution. Hereby the toothed wheel 51, whichis arranged on the same shaft as the wheel 55 and is rigidly connectedthereto, is turned the wheely 51 in turn advancing the toothed wheel I8rigidly connected with the units drum I of the series of drumsindicating the number of the year so that said drum is turned 1/10 of arevolution. The new number of the year now appears.

Arranged on the same shaft as the toothed wheels 55 and 51 and rigidlyconnected thereto is a cam wheel 59 having such a shape that one fourthof its periphery has a greater radius than the remaining portion thusforming a cam surface 60. The lower portion of the periphery isapproximately on a level with the bottom of the notch 48. On everyfourth shifting of the year the cam surface 60 will cover part of thenotch 48 radially. The entire group of wheels 55, 51

and 59 is retained in the set position by a snap spring 8| which issecured to the ratchet wheel I2 and engages two of the teeth of thewheel 55'.

During a leap year the cam surface 60 covers part of the notch 48 (thedriving notch for the l5,i

month of February), so that when the month drum is advanced to theposition of February the feed pawl 21 will be prevented by the cam 60from reaching the bottom of the notch 48 and will engage the notch 50 inthe sector I8 (Figure 1o:-

24) instead of the notch 5I as in ordinary years. The wheel I9 will thenbe advanced 2/30 of a revolution instead of 3/30, and the month shiftingmechanism will be released rst after the date numeral 29 has appeared inthe aperture 15.,

(Figure When shifting to the month of March the sector I8 has in thiscase to pass a 1/3 shorter way in returning to its initial position, andconsequently the sector will drive the wheel 6 by means of the planetarygear only 2A; of its 20 movement during an ordinary year. Hereby thedate will be advanced two days instead of three, and accordingly to thenumeral 31 also in this case. Thereafter the same operations as duringan ordinary year will be performed. 25

The advancing of the tens and hundreds digits of the number of the yearis effected in the same manner as the advancing of the tens digits ofthe date except that the drums indicating the number of the year areshaped as decagons.

From the above it will be clear that there exists a reciprocal actionbetween the advancing of the date ratchet wheels and of the registerwheel I9 forming the outer wheel in the planetary gear, the date ratchetwheels and the register wheel being locked against rotation in oppositedirections so that a movement of the sector I8 in one direction effectsan advance of the register wheel I9 and a movement of the sector I8 inthe other direction effects an advance of 40 the date wheels.

When shifting to a month having 31 days from a month having a lessnumber of days a double advancing of the date drums is effected, firstlyduring the advance movement of the arm 28 i5 through the intermedium ofthe planetary gear, the unit drums being then advanced from 8, or 9, or0, to 1 secondly during the return movement of the arm 28, the tensdrurn being then advanced one step, viz. from 3 to 0, whereas the 50unit drum remains on 1. On all other days the date drums are actuatedonly at the return movement of the arm 28.

The construction of the mechanism is based on the assumption that in thecalendar a month having less than 31 days is both preceded and followedby a month having 31 days, i. e., that two short months do not followimmediately upon each other. This is the case in the Gregorian and theJulian calendars. 60

The turning magnet for turning the spindle 2 described above and shownon the drawings forms no essential element of the invention but can bereplaced by any other suitable electrical or mechanical arrangementcapable of giving to the spindle 2 a turning impulse of one seventh of arevolution against the action of a restoring spring. Similarly, thedifferential or planetary gearing and several details of the mechanismmay be made otherwise than shown without receding from the fundamentalidea of the invention.

What I claim is:

1. A calendar mechanism comprising a rotatable indicator of vdates and arotatable indiv cator of names of months, a month shifting mechanism, asource of driving impulses intermittently connected to said indicators,a diierential gear having a sun wheel, connected to said indicator ofdates, a second sun wheel or register wheel controlling said monthshifting mechanism, a planetary wheel determining by its positioncorresponding positions of said register wheel, and means for movingsaid planetary wheel 'at the beginning of every month in a positioncorresponding to the length of said month, locking the planetary wheelthere and releasing it at the end of the month.

2. A calendar mechanism comprising date and month indicator drumsjournalled on a common oscillating spindle, serving as a source ofimpulses; a month shifting mechanism; a differential gear, having a sunwheel connected to said date indicator drum, a planetary wheeljournalled in a ratchet sector, pivoted around said spindle, and secondsun or register wheel, pivoted around said spindle, said register wheelhaving on its periphery a notch meshing with a control pawl of saidmonth shifting mechanism, said control pawl being inserted between saidmonth indicator drum and a ratchet pawl on said spindle, said controlpawl being actuated by a lever, which is arranged in the way of pins onsaid date indicator drum, said first sun wheel, planetary wheel andsecond sun or register Wheel having a ratio of gearing of 111:3.

3. A calendar mechanism comprising date and month indicators journalledon a common driving spindle, a month shifting mechanism and adifferential gear inserted between said date indicator and said monthshifting mechanism, the date tens wheel and the date units wheel beingactuated by a common driving pawl on said spindle, said driving pawlhaving an arm reaching within the periphery of said date units wheel,said arm being adapted to be 'lifted at shifting the date from 0 to 1 bymeans of a pin on said date units wheel, the notch of said date unitsWheel for date 1 being at a greater distance from the centre than thecorresponding notch of the date tens wheel.

4. A calendar mechanism comprising date and month indicators journalledon a common driving spindle, a month shifting mechanism and adifferential gear inserted between said date indicator and said monthshifting mechanism, the date tens wheel and the date units wheel beingactuated by a common driving pawl, the periphery of said date unit wheelbetween the notches for dates 1 and 2 having smaller radius than thecorresponding notch of said date tens wheel.

5. A calendar mechanism comprising date and month indicators journalledon a common driving spindle, a month shifting mechanism and adifferential gear inserted between said date indicator and said monthshifting mechanism, the date unit drum having a coupling device adaptedto once in a revolution of said date units drum actuate said date tensdrum a tenth of a revolution, a spring actuating the Octagon peripheryof said date tens drum and forcing it toI complete the movementintroduced by said coupling device.

6. A calendar mechanism comprising date, month and year indicatorsjournalled on a common driving spindle, a month shifting mechanism and adifferential gear inserted between said date indicator and said monthshifting mechanism, a double toothed Wheel being journalled on saidmonth indicator, said toothed wheel meshing with a xed pin and with atoothed wheel on said year indicator and being adapted to drive saidyear indicator one unit by each engagement.

7. A calendar mechanism comprising date, month and year indicatorsjournalled on a common driving spindle, a month shifting mechanism and adifferential gear inserted between said date indicator and said monthshifting mechanism, a double toothed Wheel being journalled on saidmonth indicator and being adapted to drive said year indicator, saiddouble toothed wheel having a cam xed thereto, said cam being adapted topartially cover the notch representing the month of February in theratchet sector of said diierential gear, thereby effecting the insertingof a day in the month of February in leap years.

AGNE KNOS HERBERT GERMUNDSSON.

